Many proposals have been made for attachment of rotary cutters to lawn mowers and other small powered garden tools for use as stump cutters or chippers. In general, however, satisfactory results are not obtainable at the small power inputs provided by such garden tools, say 3 or 4 hp. The cutters tend to bite into the wood and stall. This can to some extent be avoided by gingerly manipulating the cutter head in an attempt to control the depth of cut, but that is difficult to do, particularly since the cutter is located under the power tool and out of the user's direct line of vision.
Successful stump and root cutters are generally driven by much more powerful engines, commercial units for example often running say 35 or 50 hp. The present invention can be also be used with such higher horsepower drives, if desired.